By announcing his plans to run for re-election in the Assembly, Hall is forcing out Carson Councilman Mike Gipson. Hall had previously endorsed Gipson's bid to succeed him in the Assembly.

"I'm not gonna run against my incumbent and my friend," Gipson said.

Hall's announcement also creates trouble for Assemblyman Warren Furutani, who is running for the L.A. City Council.

Redistricting has left Furutani without a district. Should Furutani lose to Joe Buscaino -- a strong possibility -- he might have considered running for re-election from Hall's district. But with Hall back in the race, that seems like a remote possibility. Furutani said he would deal with that after the Jan. 17 council runoff, if he has to.

"I'm focused on one thing and that's the L.A. City Council race," Furutani said.

The Congressional race will now be a one-on-one matchup between Hahn and Richardson. Thanks to the top-two primary system, the two candidates will likely face each other twice -- once in June and once in November.

Richardson, who has faced a series of ethics problems, will be fighting to hang on to the third African-American seat in Los Angeles.